The synthesis, characterization and catalytic application of manganese porphyrins bonded to novel modified SBA-15

Article abstract of DOI:10.1039/c8nj00743h

In the presented research, a highly ordered mesoporous silica material (SBA-15) was functionalized with imidazole as a functionalizing reagent (SBA-TMSIm) and then characterized via FT-IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffra

Full text of DOI:10.1039/c8nj00743h

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ISSN 1144-0546
PAPER
Jason B. Benedict et al.
The role of atropisomers on the photo-reactivity and fatigue of
diarylethene-based metal–organic frameworks
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Synthesis, characterization and catalytic application of manganese
porphyrins bonded to the novel modified SBA-15
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
b
Saeed Rayati,* Parinaz Nafarieh and Mostafa M. Amini
DOI: 10.1039/x0xx00000x
In the present research, a highly ordered mesoporous silica material (SBA-15) was functionalized with imidazole as a
functionalizing reagent (SBA-TMSIm) and then characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA),
powder X-ray diffraction (XRD) and nitrogen adsorption/desorption isotherm. The SBA-TMSIm was used as a support for
coordinative anchoring of tetraphenylporphyrinato-manganese(III) acetate [Mn(TPP)OAc] via axial ligation. The prepared
catalyst was characterized by different spectroscopic methods and the amount of loaded metalloporphyrin on SBA-TMSIm
was determined by atomic absorption spectroscopy. Finally, the immobilized metalloporphyrin was found to be an
efficient catalyst in the oxidation of styrene with molecular oxygen and isobutyraldehyde (IBA) as the co-oxidant. In
addition to that, this aerobic oxidation system was used to oxidize various olefins and the results showed their epoxide
www.rsc.org/
was
the
major
products.
9
,10
chain.
On the other hand, axial base assists the molecular
Introduction
oxygen via π-donation to coordinate more readily to the metal
center, which leads to significant increase in the aerobic
oxidation yield. The basicity of the proximal ligand is also a
determining factor in dioxygen complex formation. It has
studied that in manganese-porphyrins the strong π-donor
In the past few decades, the use of toxic and harmful oxidants
in the oxidation reactions would dramatically decrease the
qualification of systems from environmental-friendly
approaches. Among of the different sources of oxygen, use of
non-polluting oxygen donors, such as molecular oxygen in
hydrocarbon biomimetic oxygenation, is of particular
imidazole is the best nitrogen donor among the others, which
11-13
would increase the oxygen-metal affinity.
Axial bases can
directly add to the reaction atmosphere or it may attach to the
metal center from the first place.
1
-4
interest.
One of the most important challenges is the
with transition metal
Metalloporphyrins can partially decompose during the
activation process of molecular O
2
catalytic
metalloporphyrins onto solid organic and inorganic supports is
well-structured way to bridge the gap between
process.
Therefore,
immobilization
of
complexes to perform a number of reactions including the
highly selective oxidation of different substrates. A number of
first-row transition metals ions (such as Mn, Fe, Cu) which are
a
heterogeneous and homogeneous catalytic systems.
Heterogeneous phases are preferred with clarity due to their
advantages of stability in reaction phase against temperature
and pressure changes and the ability to separate from reaction
employed by metalloenzymes are capable of activating
5
molecular O .
2
Manganese porphyrins have been extensively used as efficient
catalysts for oxidation of alkenes with molecular O as a green
oxidant. Early works demonstrated that simple biomimetic
metalloporphyrins can bind much easier to O in the presence
6
2
solution for later use. However, the system efficiency slightly
6
-8
decreases because of not being able to achieve all of the active
14,15
2
sites of the catalyst.
Modifying solid supports with donor
of donor bases coordinated through the axial site as a
mimicking of proximal histidine nitrogen bonding structure for
hemoglobin and myoglobin anchored in a cleft in the globin
groups can significantly improve the catalytic properties in
comparison with non-modified supports due to the
combination of two different catalytic sites in one material.
Recent works on some supports from bulk to nano modified by
groups such as pyridine and imidazole have been
1
6,17
performed.
Santa Barbara Amorphous (SBA-15) is a special type of ordered
mesoporous silica support with unique and significant
properties of the large pore size, thick pore walls (4-6 nm),
thermal and mechanical stability, highly ordered
mesostructured, large specific surface area (700-1000 m2/g)
and easy synthesis, which make it a beneficial catalyst support
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1
8-20
for wide applications.
In spite of favourable functions of capillary column HP-5 (phenyl methyl siloxane 30 m × 0.32 mm
SBA-15 in catalysis, it would be requested to modify SBA-15 to × 0.25 μm).
enhance and optimize its catalytic activity by supporting or
immobilizing on other elements or complement other catalyst, Preparation of the heterogenized catalyst
especially for thermal toleration and reusability. In addition,
SBA-15 is one of the best materials to be modified and
Preparation
of
[H TPP],
[Mn(TPP)OAc]
and
5-((3-
2
functionalized because it has a controllable pore size, pore
volume and high surface area. A study of functionalizing SBA-
(
trimethoxysilyl)propyl) carbamo- yl)-1H-imidazole-4-carboxylic
acid (TMSIm) Meso-tetraphenylporphyrin [H
2
prepared according to the literature. The [Mn(TPP)OAc] was
2
TPP] was
1
5 with various groups such as sulfonic, amino propyl,
2
5
1-23
imidazole, triazole group has investigated recently.
The
prepared and characterized according to the already reported
combination of the SBA-15 with terminal imidazole group
enables a good chance to design and synthesize novel
2
6
procedure for metalation of porphyrins. For the synthesis of
supported metalloporphyrins to mimic the function of P-450 imidazole functionalizing reagent (TMSIm), in a 250 mL round-
enzymes, and simultaneously reach the desirable features of bottomed two-necked flask equipped with a magnetic stirrer
heterogeneous systems.
and a condenser, 16 mmol (2.5 g) of 4,5-imidazoledicarboxylic
In this perspective, first imidazole reagent [5-((3- acid were suspended in 100 mL of dry CH Cl under N2
2
2
(
trimethoxysilyl)propyl)carbamoyl)-1H-imidazole-4-carboxylic
atmosphere. A total of 5 mL of oxalyl chloride was slowly
added from a dropping funnel. After 12 h, the solvent was
removed under reduced pressure and the residue was
acid] (TMSIm) was prepared as the SBA-15 functionalizing
agent. Then the [SBA-TMSIm] modified support were
synthesized and characterized and was utilized as a support for
suspended again in 100 mL of dry CH
2 2
Cl . After the addition of
[
Mn(TPP)OAc] for the oxidation of styrene and various olefins
7
mL of triethylamine to the reaction mixture, 4.0 g of 3
2
in isobutyraldehyde/O system.
aminopropyltrimethoxysilane was slowly added. The reaction
mixture was stirred at room temperature for a further 4 h. The
mixture was suspended in water for 1 h in order to remove the
formed salts and any impurities. Then the organic phase was
separated and the solvent was removed under reduced
pressure to obtain brownish viscous oil. To avoid hydrolysis,
Experimental
Instruments and reagents
1
00 mL of dried toluene added to the product and kept in the
fridge. The formation of the imidazole-functionalizing reagent
1
Chemicals were purchased from Merck or Fluka and used
without further purification. The UV-Vis spectra were recorded
1
3
confirmed by H NMR spectroscopy. H NMR (CDCl , ppm):
on a PerkinElmer Lambda 25 UV-Vis spectrophotometer. The 0.61 (t, 2H), 1.53 (m, 2H), 3.21 (t, 2H), 3.60 (s, 9H), 8.22 (s, 1H),
solid samples were identified by X-ray powder diffraction 8.91 (s, 1H), 12.21 (s, 1H) and 12.98 (s, 1H).
(
XRD) using a STOE diffractometer with Cu-K
.15418 nm) at 40 kV and 40 mA. The diffraction patterns Preparation of imidazole functionalized SBA-15 (SBA-TMSIm) To
were recorded in the Bragg angle (2θ) range from 0.5° to 10° functionalize SBA-15 by imidazole, the general procedure was
α
radiation (λ =
0
for small angle XRD with a position sensitive detector using a
used. Briefly, SBA-15 (1.0 g) was suspended in 50 mL toluene,
the mixture was stirred for 1 h, and then 2.0 g of TMSIm was
added and refluxed for 24 h. The white solid was removed
from the solvent by filtration, washed with toluene and
ethanol, and then dried at room temperature. The formation
of this nanoporous silica was confirmed by FT-IR spectroscopy,
low angle X-ray powder diffraction (XRD) and thermal analysis.
step size of 0.06°. Infrared spectra were recorded (KBr pellets)
-1
on an ABB Bomem: FTLA 2000-100 in the 400 to 4000 cm
range. Thermogravimetry and differential thermal analysis
(
TGA/DTGA) were carried out on a Mettler Toledo (TGA/DTGA)
−1
2
under N atmosphere at a heating rate of 10 °C min . The
manganese content of catalyst was measured by atomic
absorption spectroscope (model GVC932) with air-acetylene
flame. Nitrogen adsorption-desorption measurements were
carried out on a BELSORP-mini II at 77 K. The samples (36 mg)
were previously degassed at 150 °C for 15 h. The specific
Preparation of [Mn(TPP)OAc/SBA
-
and SBA-TMSIm mesoporous support (0.40 g) were added to
TMSIm] [Mn(TPP)OAc] (0.10 g)
surface area was determined by the adsorption isotherm with 30 mL dichloromethane and mixed on a shaker for 30 minutes.
2
relative pressure 0.01 m /g using BET method. The pore size The mixture was allowed to react at room temperature for 24
distribution was calculated by BJH method from the h. Then the solid was filtered and washed with
desorption isotherm, and the total pore volume was obtained dichloromethane and dried in air. FT-IR, XRD, BET, TGA/DTA,
at 0.35-200 nm in pore diameter. The micro pore volume, UV-Vis, and atomic absorption spectroscopy were used to
microporous surface area, and external surface area were characterize the resulting heterogenized catalyst. The
obtained by the t-plot method. Gas chromatography (GC)
schematic preparation route of the synthesized solid support is
shown in scheme 1.
analyses were conducted on an Agilent chromatograph (model
7890B) equipped with flame ionization detector (FID) and
2
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Scheme 1 Schematic synthesis of [Mn(TPP)OAc/SBA-TMSIm].
General heterogeneous oxidation procedure
carried out in a 5-mL test tube in a high temperature water
bath keeping the temperature between 40-50 C. In a typical
°
procedure, to 1 mL of acetonitrile, 0.0021 mmol of prepared
Catalytic performance of [Mn(TPP)OAc/SBA-TMSIm] was
Results and discussion
Characterization of imidazole functionalized SBA-15 (SBA-TMSIm)
FT-IR spectra. FT-IR spectrum of [SBA-TMSIm] in addition to the
2
1,27-29
typical bands of mesoporous silica,
asymmetric and
symmetric Si–O–Si characteristic stretching vibrations at 1076
−
and 800 cm along with Si–OH at 950 cm and Si–O–Si
1
−1
−1
bending at 458 cm , showed new bands at 3422, 2929, 1648,
−
1
1
551 and 1420 cm . These bands, which are corresponded to
C–H aromatic, C–H aliphatic, C=O, C=N and C=C, respectively,
confirmed 5-((3-(trimethoxysilyl)propyl)carbamoyl)-1H-
imidazole-4-carboxylic acid groups’ successfully immobilized
3
0
Figure 1 FTIR spectra of (a) SBA-15 and (b) [SBA-TMSIm].
into SBA-15 (Figure 1).
catalyst, 0.0189 mmol of substrate and 0.0567 mmol of
isobutyraldehyde as a co-reagent were added. The mixture
was stirred slowly by magnetic stirrer under oxygen
atmosphere (pure oxygen gas balloon directly attached to the
reaction system) for 1 h. After reaction completed, solid phase
was separated by centrifugation and the products were
characterized by GC.
X-ray diffraction. Low-angle XRD patterns of SBA-15 before and
after imidazole-modified exhibit a single and strong diffraction
peak at 2θ between 0.5 and 1.5° as seen in Figure 2, which can
be indexed to the (100) hkl reflection, indicating the presence
of a mesoporous structure. This reflection is associated with
the P6mm hexagonal symmetry typical of SBA-15 material and
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according to thermal analysis, the prepared compound is
stable up to 403 °C.
Nitrogen adsorption/desorption isotherm and pore size
distribution curve studies
. Dinitrogen adsorption-desorption
isotherms of SBA-15 and [SBA-15TMSIm] at 77 K are shown in
3
4
Figure 4. A type IV profile with a type H1 hysteresis loop
which is characteristic of 1D cylindrical regular pores and
capillary condensation were observed on the isotherms of
both solids which is typical of mesoporous materials, according
2
1,28,29,35-40
to IUPAC classification in the literature.
The pore size
distribution curves of SBA-15 and [SBA-TMSIm] (Figure 5)
obtained by the Barrett-Joyner-Halenda method shows narrow
and uniform-sized mesopores with an average value of 4.6 nm
2
1,35,36
Figure 2 Low-angle XRD pattern of (a) SBA-15 and (b) [SBA-TMSIm].
for both solids.
The specific surface area (SBET), estimated
statitical thickness of adsorbed layer (2t) and pore volume (V
of SBA-15 and [SBA-TMSIm] are shown in Table 1. The BET
P
)
indicating a significant degree of long-range ordering in the
3
1
structure and a well-formed hexagonal lattice. Due to the
grafting of TMSIm groups, the diffraction peak of [SBA TMSIm]
ꢀ
shifted to a higher angle and became weaker compared with
unmodified one. These results indicate that the mesoporous
phase of the compound was maintained, while the integrity of
the mesoporous structure was affected by the incorporation of
6
4
2
00
00
00
0
(
a)
3
2
TMSIm functionalizing agent.
TGA/DTGA analysis. The thermal stability of [SBA-TMSIm]
compound (Figure 3) was studied by TGA/DTGA analysis. The
total weight loss was measured to be 10.3% during pyrolysis in
(
b)
N
2
. The differential thermogravimetric analysis (DTGA) curve of
[SBA-TMSIm] showed two distinct weights loss centered at 267
and 403 °C. The first one is attributed to the loss of free water
molecules, which are accommodated in cylindrical pores,
which are maintained in the pores up to the temperature
higher than that applied in the sample preparation for sorption
0
0.3
0.6
0.9
p/p
0
Figure 4 The nitrogen adsorption/desorption isotherms of (a) SBA-15 and (b)
[
SBA-TMSIm].
3
3
measurements. These water molecules can release from 100
up to 200 °C, and in this DTGA curve, they seem to be
released at 267 °C with 4.1% weight loss. A weight loss
occurred between 200 and 800 °C which is accompanied with
a district peak at 403 °C in the DTGA curve, corresponds to
the oxidative decomposition of the organic part of 5-((3-
Table 1 Textural properties of SBA-15 and [SBA-TMSIm]
a
2
-1
b
2t /nm
c
Vp /cm g
3 -1
Solid
S
BET /m g
SBA-15
551
3.6
7.8
1
[
SBA-TMSIm]
347
0.66
(
trimethoxysilyl)propyl)carbamoyl)-1H-imidazole-4-carboxylic
a
S
BET is the BET specific surface area.
b
c
acid. Moreover, this ~6.2% weight loss is corresponded to
2t is estimated statistical thickness of adsorbed layer.
is pore volume, obtained by BJH method
V
P
.
~
0.26 mmol/g loading of TMSIm on SBA-15. Furthermore,
Figure 3 TGA/DTGA curves of [SBA-TMSIm].
4
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1.2
0.9
0.6
0.3
0
4
.6
(
a)
(
b)
(b)
(
a)
0
5
10
rp (nm)
15
1
2
3
4
5
6
7
8
9 10
2
θ (ᵒ)
Figure 5 The pore size distribution curves by BJH method for (a) SBA-15
and (b) [SBA-TMSIm].
Figure 7 Low-angle XRD patterns of (a) [Mn(TPP)OAc/SBA-TMSIm]
and (b) SBA-15.
specific surface area and pore volume of the precursor
Characterization of [Mn(TPP)OAc/SBA-TMSIm]
2
-1
3
-1
mesoporous silica SBA-15 were of 551 m g and 1 cm g ,
respectively. The experimental data show that, at a given
pressure, the thickness of the film increases upon decreasing
FT-IR spectra. Comparing the FT-IR spectra of functionalized
[SBA-TMSIm] and [Mn(TPP)OAc/SBA-TMSIm] (Figure 6) reveals
the pore volume (V
5 has a contribution of 20% of micropores. The values of at 1460-1650 cm which confirms the attachment of
micropore volume, microporous surface area and external manganese porphyrin to mesoporous silica support. The
p
). As calculated from t-plot method, SBA-
the appearance of C=C and C=N stretching bands of porphyrin
-1
1
3
-1
2
-1
2
-1
surface area were of 1.03 cm g ,377 m g , and 581 m g , similarity between FT-IR spectra of functionalized porous
respectively. The covalent modification of SBA-15 with materials and heterogenized catalysts indicates that the
imidazole moieties to yield [SBA
-
TMSIm] was followed by a porous nature of the [SBA-TMSIm] has been kept after
immobilizing the [Mn(TPP)OAc] onto them.
decrease in the BET specific surface area and pore volume to
2
-1
3
-1
3
47 m g and 0.66 cm g , respectively (Fig. 5a and b). These
decreases can be explained by the presence of 5-((3-
trimethoxysilyl)propyl)carbamoyl)-1H-imidazole-4 carboxylic
acid agent (TMSIm) that may block the access of N gas to the
The values of
micropore volume, microporous surface area and external
X-ray diffraction. Figure 7 shows the low-angle XRD pattern of
[Mn(TPP)OAc/SBA-TMSIm] and SBA-15. Apparently, after
(
2
2
8,34,36,40,41
SBA-15 pores or to the porous surface.
3
-1
2
-1
surface area for [SBA-TMSIm] were of 0.61 cm g ,175 m g ,
2
and 398 m g . Microporous surface area and No changes in
-1
the diameter of the average pore (D ) between SBA-15 and
p
[
SBA-15-TMSIm] were noticed, which is unlike to the data
3
7,41-43
reported before.
This may be related to a much lower
-1
functionalization of [TMSIm] on SBA-15 (0.26 mmol g ) in
2
compare to previous works.
8,35,41,43
Figure 8 TGA/DTGA curves of [Mn(TPP)OAc/SBA-TMSIm].
functionalization of SBA-15 and grafting Mn(TPP)OAc, the
intensity of diffraction peak decrease to some extent. This
decrease can be attributed to the disordering of catalyst
particles, and small shift to higher angle confirms the
anchoring of porphyrin into SBA-15 cavities with preservation
of the mesostructure.
TGA/DTGA
analysis.
Thermogravimetric
analysis
of
[Mn(TPP)OAc/SBA-TMSIm] exhibits the thermal behaviour of
the final heterogeneous catalyst (Figure 8). Four weight loss
events took place in the TGA/DTGA diagram. The first event at
1
62 °C with about 1.2% weight loss is related to the physical
Figure 6 FTIR patterns of [Mn(TPP)OAc/SBA-TMSIm].
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desorption of the water molecules in the [Mn(TPP)OAc/SBA- specific surface area along with the texture of
TMSIm]. The second step is associated with the loss of free [Mn(TPP)OAc/SBA-TMSIm] are listed in Table 2. The values of
water molecules, which are inside cylindrical pores, or water micropore volume, microporous surface area and external
molecules that established a link through hydrogen bonding
1
2
with SiO and released at 267 °C as mentioned before. Finally,
the mass decline around 387 °C can be attributed to the
decomposition of [Mn(TPP)OAc] and the (TMSIm) agent
together.
0.8
0
0
.6
.4
(a)
b)
Nitrogen adsorption/desorption isotherm and pore size
distribution studies. Dinitrogen adsorption-desorption
isotherms of [Mn(TPP)OAc/SBA-TMSIm] at 77 K are shown in
Figure 9. Once more, a type IV profile with a type H1 hysteresis
loop observed for this catalyst similar to the modified SBA-
0.2
0
(
350
450
550
650
750
3
4
Wavelength (nm)
15. The pore size distribution curves of [Mn(TPP)OAc/SBA-
TMSIm] (Figure 10) shows narrow and uniform-sized
mesopores with an average value of 4.6 nm similar to the solid
support. The BET
Figure 11 UV-Vis absorption spectra of (a) [Mn(TPP)OAc/SBA-TMSIm]
and (b) [SBA-TMSIm] in dichloromethane.
3
-1
2
-1
2
-1
300
200
100
0
surface area were of 0.34 cm g ,79 m g , and 122 m g ,
respectively. As expected, a decrease in the BET specific
surface area and pore volume in comparison to the SBA-15 is
clear.
UV-Vis spectroscopy. The presence of Mn-porphyrin in the
functionalized SBA-15 was also confirmed by UV–Vis
spectroscopy (Figure 11). No absorption band was observed in
the UV–Vis spectrum of [SBA-TMSIm] [Figure 11(b), dash line].
However, the Soret band at 480 nm and Q bands at 583 and
6
22 nm appear after anchoring of [Mn(TPP)OAc] into
0
0.3
0.6
p/p0
0.9
cylindrical pores of [SBA-TMSIm] [Figure 11(a)].
nm appear after anchoring of [Mn(TPP)OAc] into cylindrical
pores of [SBA-TMSIm] [Figure 11(a)].
Figure
9
The nitrogen adsorption/desorption isotherms of
[
Mn(TPP)OAc/SBA-TMSIm].
Atomic absorption spectroscopy (AAS). The manganese content
of heterogeneous catalyst was measured by atomic absorption
spectroscopy. Based on this analysis, the Mn content of the
catalyst is about 120 μmol/g (87 mg of [Mn(TPP)OAc] per 1 g).
Table 2 Textural properties of [Mn(TPP)OAc/SBA-TMSIm]
2
-1
3 -1
Solid
S
BET/m g
2t/nm
6.1
V
p
/cm g
[Mn(TPP)OAc/SBA-TMSIm]
170
0.37
Catalytic studies
a
b
c
Styrene is a standard substrate for studying the catalytic
performance for the homolytic activation of C=C in alkene
oxidation, and for estimating yield selectivity toward styrene
oxide with respect to further oxidation products. Moreover,
S
BET is the BET specific surface area.
t is estimated statistical thickness of adsorbed layer
is pore volume, obtained by BJH method
2
.
V
P
.
4
4,45
styrene oxide is an essential organic intermediate.
0
0
0
.3
.2
.1
0
Therefore, the quest for discovering systems that are capable
of catalyzing styrene and other alkenes under mild conditions
still stands a challenge for academic researchers.
4.6
The heterogenized manganese porphyrin [Mn(TPP)OAc/SBA-
TMSIm] was evaluated as a catalyst for styrene oxidation using
molecular oxygen as a green oxidant and isobutyraldehyde
(IBA) as a co-reducer. We performed a blank experiment with
3
0 mmol styrene and 90 mmol of isobutyraldehyde in
0
5
10
rp (nm)
15
20
acetonitrile at 50 °C, which afforded styrene oxide (3%) after 1
h according
Figure 10 The pore size distribution curves by BJH method for
Mn(TPP)OAc/SBA-TMSIm].
[
6
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corresponding epoxide as the sole product at 50 °C after 1 h.
Table 3 Effect of time and temperature in oxidation of styrene with molecular oxygen
catalyzed by [Mn(TPP)OAc/SBA-TMSIm] in acetonitrile
Proposed mechanism
Entry
Temp.
ᵒC)
Time
(h)
Conv. (%)
Yeild (%)
Benzaldehyde
The mechanism for the metalloporphyrin-catalyzed aerobic
oxidation of olefins such as styrene in the presence of
isobutyraldehyde generally involves a free radical process and
(
Epoxy
styrene
1
2
3
4
5
6
7
8
25
25
25
25
25
40
40
50
4
5
3
3
-
4
6
12
20
31
70
27
80
90
7
5
isobutyraldehye is a common reducing agent. In the
proposed Mechanism (Scheme 2), two pathways could be
6
10
17
41
11
30
21
10
14
29
16
50
69
4
7
7
occurred. (i) Mn(III)(TPP) reacts with the aldehyde to
generate an acyl radical (a) and Mn(II)(TPP) (pathway I in
scheme 2) and then the acyl radical react with molecular
oxygen to generate acylperoxy radical (b) which is capable for
the oxidation of alkenes. (ii) Mn(II)(TPP) reacted with peroxy
acid (c), which is generated
24
1
2
1
a
The reaction conditions are as follows: 0.0021 mmol of catalyst, 0.0189 mmol of
styrene, 0.0567 mmol of isobutyraldehyde.
to GC analysis. However, the addition of a catalytic amount of
[Mn(TPP)OAc/SBA-TMSIm] (0.0021 mmol) to the acetonitrile
mixture led to 90% conversion of styrene to styrene oxide or
benzaldehyde under the same conditions.
In order to optimize the reaction conditions, the effect of
reaction time and temperature on the oxidation of styrene was
investigated. It is observed that the highest conversion of
styrene (70%) was obtained after 24 h at 25
°C (Table 3, entry
5) while at 50 °C after 1 h 90 % conversion of styrene was
obtained (Table 3, entry 8). In addition, it is observed that
product selectivity is dependence to the reaction temperature.
At the room temperature, benzaldehyde is the major product
while at 50 °C epoxy styrene is the major product.
Homogeneous oxidation of styrene with molecular oxygen in
the presence of Mn(TPP)OAc and in the same conditions, led
to process not only did not cause catalyst deactivation but also
improve the catalytic performance.
Having proved the activity and stability of [Mn(TPP)OAc/SBA-
TMSIm] in the model reaction, the scope of the protocol was
subsequently extended to a range of olefins, as shown in
Figure 12. In this catalytic system, the oxidation of cyclooctene
Scheme 2 Plausible mechanism of styrene oxidation catalyzed by Mn(III) porphyrin in
the presence of molecular oxygen and isobutyraldehyde.
from the reaction of (b) with another aldehyde molecule, to
generate high-valent Mn(IV) porphyrin(d) (pathway II in
scheme 2) which has a high oxidizing power to form the
oxidation products.
(59%), 4-methoxy styrene (81%) and cis-stilbene (40%) give the
1
00
80
60
40
20
0
Conclusions
In summary, new and efficient mesoporous imidazole-
functionalized SBA-15 were synthesized and characterized and
its use as support for immobilization of [Mn(TPP)OAc] within
axial coordination was discussed. The heterogeneous catalyst
[Mn(TPP)OAc/SBA-TMSIm] is a well-organized system for
oxidation of olefins with high conversion yields and nice
selectivity. Molecular oxygen balloon was used as an
environmentally friendly oxidant in the reactions and due to its
inert triplet system, isobutyraldehyde was utilized as an
activator for the oxidant.
Conversion %
Epoxide Selectivity %
Figure 12 Epoxidation of various olefins using O
2
/IBA as oxidant, catalyzed by
[
Mn(TPP)OAc/SBA-TMSIm] in CH CN at 50 ᵒC temperature.
3
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5 D. Adler, F. R. Longo, J. D. Finarelli, J. Golldmacher, J. Assour,
L. Korsakoff, J. Org. Chem., 1976, 32, 476-476.
Conflicts of interest
“
There are no conflicts to declare”.
26 J. W. Buchler, G. Eikellmann, J. Puppe, K. Rohback, H.
Schneehage, and D. Weck Justus Liebigs Ann.Chem. 1971,
7
45, 135-151.
7 X. Shi, B. Fan, H. Li, R. Li, W. Fan, Micropor. Mesopor. Mater.,
014, 196, 277-283.
2
Acknowledgements
2
Financial support of this work by K.N. Toosi University of 28 S. Alavi, H. Hosseini-Monfared, M. Siczek, J. Mol. Catal. A
Chem., 2013, 377, 16-28.
Technology Research Council and Iran National Science
2
3
9 S. Hashemikia, N. Hemmatinejad, E. Ahmadi, M. Montazer, J.
Colloid Interface Sci., 2015, 443, 105-114.
Foundation (INSF) under grant No. 96005913 is acknowledged.
,
0 R. Tayebee, M. M. Amini, M. Akbari and A. Aliakbari, Dalton
Trans., 2015, 44, 9596-9609.
31 R. Tayebee, M. M. Amini, S. Pouyamanesh and A. Aliakbari,
,
References
Dalton Trans., 2015, 44, 5888-5897.
2 M. Behbahani, A. A. Akbari, M. M. Amini, and A. Bagheri,
Anal. Methods, 2014, , 8785-8792.
3 J. Li, L. Wang, T. Qi, Y. Zhou, C. Liu, J. Chu, and Y. Zhang,
Micropor. Mesopor. Mater., 2008, 110, 442-450.
4 M. Thommes, K. Kaneko, A. V. Neimark, J. P. Olivier, F.
Rodriguez-Reinoso, J. Rouquerol, and K. S. W. Sing, Pure
Appl. Chem., 2015, 87, 1051-1069.
5 Q. Zhu, S. Maeno, R. Nishimoto, T. Miyamoto, M. Fukushima,
J. Mol. Catal. A Chem., 2014, 385, 31-37.
1
H. B. Ji and X. T. Zhou, Biomimetics Learning from Nature,
ed. A. Mukherjee, Vukovar, Croatia, 2010.
D. J. C. Constable, P. J. Dunn, J. D. Hayler, G. R. Humphrey, J.
L. Leazer, R. J. Linderman, K. Lorenz, J. Manley, B. A.
Pearlman, A. Wells, A. Zaks, and T. Y. Zhang, Green Chem.,
3
3
3
6
2
2
007,
C. Parmeggiani, and F. Cardona, Green Chem., 2012, 14, 547-
64.
9, 411-420.
3
4
5
6
5
3
3
3
3
3
X. T. Zhou, H. B. Ji, H. C. Xu, H. L. X. Pei, L. F. Wang and X. D.
Yao, Tetrahedron Lett., 2007, 48, 2691-2695.
6 D. Zhao, J. Feng, Q. Huo, N. Melosh, G. H. Fredrickson, B. F.
Chmelka, G. D. Stucky, Science, 1998, 279, 548-552.
7 E. Sujandi, E. A. Prasetyanto, S. C. Lee, S. E. Park, Micropor.
Mesopor. Mater., 2009, 118, 134-142.
S. Sahu, and D. P. Goldberg, J. Am. Chem. Soc., 2016, 138
1410-11428.
H. M. Neu, J. Jung, R. A. Baglia, M. A. Siegler, K. Ohkubo, S.
Fukuzumi, and D. P. Goldberg, J. Am. Chem. Soc., 2015, 137
614-4617.
,
1
,
8 D. Zhao, J. Sun, Q. Li, G.D. Stucky, Chem. Mater., 2000, 12
75-279.
9 S. M. L. Santos, K. A. B. Nogueira, M. S. Gama, J. D. F. Lima, I.
,
4
2
7
8
B. Fu, H. C. Yu, J. W. Huang, P. Zhao, J. Liu, L. N. Ji, Journal of
Molecular Catalysis A: Chemical, 2009, 298, 74-80.
Y. Fei. Li, C. C. Guo, X. H. Yan, and Q. Liu, J. Porphyrins
Phthalocyanines, 2006, 10, 942-947.
T. L. Poulos, Chem. Rev., 2014, 114, 3919-3962.
0 R. A. Baglia, J. P. T. Zaragoza, and D. P. Goldberg, Chem. Rev.
J. Silva, D. C. S. Azevedo, Micropor. Mesopor. Mater., 2013,
180, 284-292.
0 M. J. Nasab, A. R. Kiasat, RSC Adv., 2015, 5, 75491-75499.
1 J. Q. Wang, L. Huang, M. Xue, Y. Wang, L. Gao, J. H. Zhu, Z.
Zou, J. Phys. Chem. C., 2008, 112, 5014-5022.
2 M. J. Nasab, A. R. Kiasat, RSC Adv., 2015, 5, 75491–75499.
3 A. Schlossbauer, D. Schaffert, J. Kecht, E. Wagner, T. Bein, J.
Am. Chem. Soc., 2008, 130, 12558-12559.
4 M. Selvaraj, S.W. Song, S. Kawi, Micropor. Mesopor. Mater.,
4
4
9
1
2
017, 117, 13320-13352.
4
4
1
1
1
1
1
1
1
1 S. Rayati a, S. Zakavi, V. Noroozi, S. H. Motlagh, Catalysis
Communications, 2008, 10, 221-226.
2 O. Pouralimardan, A. C. Chamayou, C. Janiak, H. Hosseini-
Monfared, Inorg. Chim. Acta, 2007, 360, 1599-1608.
3 M. Ghorbanloo, H. Hosseini-Monfared, C. Janiak, J. Mol.
Catal. A: Chem. 2011, 345, 12-20.
4
4
4
4
2
008, 110, 472-479.
5 B. Tyagi, B. Shaik, and H. C. Bajaj, Appl. Catal. A: General,
010, 383, 161-168.
2
4 S. Nakagaki, K. M. Mantovani, G. S. Machado, K. A. D. F.
Castro, and F. Wypych, Molecules, 2016, 21, 291.
6 Yu. Rongbing, S. Zhang, Y. Luo, R. Bai, J. Zhou, H. Song, New J.
Chem., 2015, 39, 5096-5099.
7 H. B. Ji, X. T. Zhou. Biomimetic Epoxidation of Olefins
Catalyzed by Metalloporphyrins with Molecular Oxygen;
INTECH Open Access Publisher, 2011.
5 E. Brule, and Y. R. Miguel, Org. Biomol. Chem., 2006,
09.
6 G. Huang, R. X. Yuan, Y. Peng, X. F. Chen, S. K. Zhao, S. J. Wei,
W. X. Guo, and X. Chen, RSC Adv., 2016, , 48571-48579.
4, 599-
6
6
7 H. Ebrahimzadeh, A. A. Asgharinezhad, N. Tavassoli, O.
Sadeghi, M. M. Amini, and F. Kamarei, Intern. J. Environ.
Anal. Chem. 2012, 92, 509-521.
1
8 W. J. J. Stevens, K. Lebeau, M. Mertens, G. van Tendeloo, P.
Cool, and E. F. Vansant, J. Phys.Chem. B, 2006, 110, 9183-
9
187.
1
2
2
2
2
9 F. Zhang, Y. Yan, H. Yang, Y. Meng, C. Yu, B. Tu, D. Zhao, J.
Phys. Chem. 2005, 109, 8723-8732.
0 N. Rahmat, A. A. Zuhairi, A. Rahman Mohamed, Am. J. Appl.
Sci. 2010,
1 F. J. V. E. Oliveira, M. A. Melo Jr., C. Airoldi, Mater. Res. Bull.,
013, 48, 1045-1056.
2 I. Sierra, D. Pérez-Quintanilla, Chem. Soc. Rev. 2013, 42
792-3807.
7, 1579-1586.
2
,
3
3 J. A. Melero, G. Morales, J. Iglesias, M. Paniagua, B.
Hernández, S. Penedo, Appl. Catal. A Gen. 2013, 466, 116-
1
22.
2
4 F. Hoffmann, M. Cornelius, J. Morell, M. Fröba, Angew.
Chem. Int. Ed. 2006, 45, 3216-3251.
8
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